Yang’s Jewish problem generated less attention on the Chinese Web than the broader question of foreigners. It’s never difficult to find a nationalist on the Chinese Web, but the proportions surprised me this week. There is a heavy vote in support of the government’s announced hundred-day campaign to ferret out the foreigners who lack the right papers. “Whether it’s foreign or domestic, the trash should be cleaned out,” as one voice put it. “Foreigners have been treated too well for too long in China; time to get used to something new,” wrote another.

This, too, shall pass. The roots of nationalism in China are deep and raw, as I described in the magazine the last time this issue erupted. But, four years later, China continues to welcome foreigners most of the time with a quirky and endearing enthusiasm. As a snapshot of a moment, it needed to be noted. Don’t cancel your trip.

Just as foreigners are often cast as villains in China, they sometimes appear as heroes. A few days before “Aijan’s” video went viral, a Good Samaritan appeared. Weibo user @MovieFactory saw a young man buy McDonald’s fries to share with an old beggar woman in Nanjing, sitting and chatting with her. “This is the most love-filled story I’ve seen today,” MovieFactory glowed. “Re-tweeted” nearly 38,000 times, this “handsome American” was soon identified as Jason Loose of Los Angeles, a student at Nanjing University. Although Loose claims he didn’t do anything special, Chinese netizens see in him an altruism lacking in their own society.

Chinese netizens sometimes compare foreigners to their own aloof citizenry. The contrast was especially startling last October, when the country watched horrifying footage of a toddler run over twice in a Guangdong street and left ignored by passersby for seven minutes before someone came to her aid. The little girl, Yueyue, died after struggling in the hospital for a week. On the same day, Uruguayan expat Maria Fernanda jumped into West Lake in Hangzhou to save a suicidal Chinese woman from drowning.

Weibo user @LiTingBalinda noted that while Fernanda was rescuing the woman, “the Chinese just gathered and watched; and when they came out of the water and the woman’s life was in the balance, the Chinese people took out their cellphones to take pictures. What kind of sick society is this?”